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Initially, we chose to show a single arrow indicating the current direction of the elevator. However, we found that our users were confused by this. Many did not seem to realize the purpose and we had several comments that the arrow was unnecessary. Since an elevator may need to go in one direction before it can take a user to a floor in the other direction, we included the arrow as an indication to the user that the elevator would not be headed to their floor immediately and that it might make sense to wait for the elevator to return before getting inside. We thought this was important feedback to give to the user so we elected to show two arrows at all times and highlight the one that represented the current direction. We thought this would better indicate there are two options.
We also considered how best to indicate which floors the elevator would travel to. When an elevator needs to travel in both directions, it may make sense for users travelling to a floor in the second direction to wait until the elevator returns to get in. We wanted to include floors in the second direction in the interface so users would know they had gone to the correct elevator. However, we did not want to display them in exactly the same way as floors the elevator would travel to immediately. While the arrow should ideally indicate to users which floors the elevator will go to first, we found that users were confused by the initial arrows, so we wanted another way to represent the fact that the elevator would not travel immediately to those floors. We decided to highlight the floors in the button array but not display them in the scrollbar. This clearly indicates there is something different about those particular floors. Seasoned users will know immediately what it means, and the discrepancy will prompt new users to look further at the interface at which point they will hopefully discover the arrows and be able to figure it out.
The third part of our interface is inside the elevator. A list of floors the elevator will be stopping at is displayed, in order. An ETA is displayed for the most proximate floor. Below this display is an emergency exit button, which will stop the elevator on the closest floor possible, even if a stop on that floor was not planned. Pressing this button also causes an alarm to sound, to dissuade users from abusing the button. Not shown in our simulation are the standard, required elevator buttons, such as emergency call. While these buttons should still be present, they aren’t relevant to our design.
We considered including an ETA for each floor the elevator was traveling to, rather than just for the most proximate floor. We decided against this for two reasons. First, having a list of countdowns all changing by one second at the exact same time looked busy and rather ugly. And second, the ETA for the floors that are further away are necessarily less accurate than the ETA for the floors that are close.
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